Variable speed feed control devices



y 1958 w. F. MORGAN ETAL 2,842,249

VARIABLE SPEED FEED CONTROL DEVICES Filed Jan. 10, 1956 11 Shegt's-Shet1 IN V EN TORS WF. MORGAN R.V. MUFFLEY w. F. MORGAN ETAL 2,842,249VARIABLE SPEED FEED CONTROL DEVICES July 8, 1958 ll Sheets-Sheet 2 FiledJan. 10, 1956 INVENTORS.

F. MORGAN .v MUFFLEY I ATTORNEY y 1958 w. F. MORGAN ET AL 2,842,249

VARIABLE SPEED FEED CONTROL DEVICES Filed Jan. 10, 1956 11 Sheets-Sheet3 IN VEN TORS.

W. F. MORGAN RV. MUFFLEY ATTORNEY July 8, 1958 W. F." MORGAN ET AL2,842,249 VARIABLE SPEED FEED CONTROL DEVICES ll Sheets-Sheet 4 FiledJan. 10, 1956 FIG.60

INVENTORS. W.F. MORGAN RV. MUFFLEY ATTORNEY y 1958 w. F. MORGAN ErAI.2,842,249

VARIABLE SPEED FEED CONTROL DEVICES Filed Jan. 10, 1956 11 Shee ts-Sheet5 FIGQSb INVENTORS.

ATTORNEY y 1958 w. F. MORGAN "ET AL 2,842,249

, VARIABLE SPEED FEED CONTROL DEVICES v Filed Jan. 10, 1956 ,11Sheets-Sheet 7 INVENTORS.

W. E MORGAN By R.V.MUFFLEY ATTORNEY July 8, 1958 Filed Jan. 10, 1956 L lI;

w. F. MORGAN ETAL VARIABLE SPEED FEED CONTROL DEVICES 11 Sheets-Sheet 8H, R29 FIG. aau

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. 2 I INVENTORJ W. F MORGAN RMMUFFLEY ATTORNEY w. F. MORGAN ET AL2,842,249

VARIABLE SPEED FEE D CONTROL DEVICES July 8, 1958 INVENTORS.

w. F. MORGAN R. v. MUFFLEY 0 ATTORNEY ll Sheets-Sheet 9 Filed Jan. 10,1956 FlG.8c

July 8,1958 w. F. MORGAN ET AL 2,842,249

- VARIABLE SPEED FEED CONTROL DEVICES Filed Jan. 10, 1956 11Sheets-Sheet 10 IN VEN TORS.

W. F. MORGAN R.V. BY MUFFLEY FIG.8d W

ATTORNEY July 8, 1958 w. F /MORGAN ETAL 2,842,249

VARIABLE SPEED FEED CONTROL DEVICES Filed Jan. 10, 1956 11 Sheets-Sheet11 MOTOR SPEED CONTROL ATTORNEY United States- Patent VARIABLE SPEEDFEED CONTROL DEVICES William F. Morgan, Vestal, N. Y., and Robert V.Mufiley, Los Altos, Calif., assignors to International Business MachinesCorporation, New York, N. Y., a corporation of New York ApplicationJanuary 10, 1956, Serial No. 558,247

Claims. (Cl. 197-133) This invention relates generally to paper feedingdevices and more particularly to continuous record form feeding meansfor operating at high speed in cooperation with a record controlledprinting machine.

This application is related to the application Serial No. 479,062, filedon December 31, 1954, by F. J. Furman et al., for Record FeedingDevices.

With the advent of high-speed printing devices such as the wire printersof the kind with which the present devices are illustrated, it becomesnecessary to provide means for advancing record material rapidly and yetwithout sudden shock of starting or stopping operation. In other Wordsthere is required a sort of harmonic feed motion with a slow startingeffect, rapid acceleration, and gradual stopping. In the presentinstance this improved form of movement is brought about by theingenious use of a variable speed drive motor, a random type of engagingclutch and a perforated feed control tape which in effect gives apreliminary warning when a feed which is about to take place exceeds orfalls short of certain spaced limits. The feed control tape is generallyof the kind set forth in the Mills et a1. Patent No. 2,531,885 and otherpatents of a similar nature, specifically, 2,569,829, 2,684,746, andapplication Serial No. 477,286, filed December 23, 1954, by J. M.Cunningham et 211., now Patent No. 2,747,717. This present structure isof an advanced form in that in addition to other differences,cooperating with the tape there are three sets of feed control brushes.There are provided the usual set of stop control brushes which sensecontrol indicia or hole positions in the tape, which is synchronizedwith the movement of the record material and thereby energize controlsfor stopping record movement wherever desired. In addition thereto arethe other two sets of tape brushes which are forms of predictors engagedby a stop perforation before it reaches the stop brushes. The first setencountered by a perforation are called interlock brushes and theyengage a tape perforation 3% inches before it reaches the stop position.Controls are exercised by these interlock brushes for callingthe'printer back into operation after suppression, and for regulatingthe amount of time which the printer is held idle to allow time forrecord material movement. The second set of preliminary brushes are forthe purpose of speed reduction, because Whenever a skipping movement ofthe record material is of any appreciable extent the drive motor isdriven at a fast speed (75 inches per second as contrasted with 25inches per second at slow speed) and it is necessary-that the speed bereduced before the feed control performation reaches the stoppingcontrol brush. In other words, the second set of preliminary brushesoperate motor controls to slow down the carriage movement before itcomes to a stop. The result is a harmonic motion which operates throughpin feed tractors to draw the continuous form rapidly without tearingthe marginal perforations; and the motion is controlled further to comegradually to a stop without shock.

Therefore, it is an object of the invention not only to provide a paperfeeding means with a high-speed driving means, but also to furnishcontrols therefor, so that rapid starting and advance movements andcontrolled stops are made possible in order to attain variable and fastspeeds of record form movement with high-speed printing.

The invention is illustrated as embodied in an efficient interlockedpaper feeding means for cooperating with a serial order printer. Theprinter is arranged with one printing head to impress on four adjacentrecord positions in the manner A B C D space H G F E space I J K L andin the order A, B, C, D, space, E, F, G, H, space, etc. Multipleprinting by each head is accomplished by the lateral motion of the printheads between impressions during the print cycle. The direction ofmotion is reversed on alternate cycles. In other words, the printer headfor printing in four adjacent orders describes ,a zig-zag path relativeto the spaced record strip while printing. Therefore, one primaryprinting cycle is divided into four subcycles, one for each of the fourimpressions which occur before spacing takes place. For ordinary linespacing operation there is no loss of printer time because printingcontinues to operate smoothly, character by character. For shortskipping or eject operations there is a saving because the printer timetaken is in terms of omissions of short subscycles rather than omissionof full primary print cycle time. Examples of the minor degrees of lossare given here:

A B C D 41301001 space=4 to 21 line spaces omit 1 subcyele omit subeyeleE I H .G F spaee=22 to 40 line spaces mint 2 subcycles omit subcycles J,K

' L M N 0 space=41 to 58 line spaces omit three subcycles omit subcyelesP, Q, R V U '1 S space=59 to 77 omit 4 subcycles=1 primary print cycle AB C D omit subcycles W, X,

Y, z From the foregoing it is noted that loss of printer time is notinvariably large as in the prior art, but rather tailored to suit theparticular extent of feeding movement. There is no more loss of timethannecessary.

Although shown and discussed in connection with serial order printingWith'fourimpressions made on one line from one printer head per mainprint cycle, it is apparent that speed of printing and feeding may beincreased by providing more printer heads and making fewer or no serialorder impressions, i. e., twice the speed with only two serialimpressions and four times the speed with no serial impressions but asolid array of printer heads with one head for each ordinal position.The speed of recording is of the order of 800 to 1,000 lines perminute-for the printer with two serial impressions. It

will be realized that many advantages of the construction revealed hereare applicable to all forms of printers with or withoutserial orderprinting and at speeds greater or less than 1,000 L. P. M.

Another objectof the invention is to provide paper feeding controls fora variable speed motor so that when it ized that the motor, inaccelerating or braking between the speed levels, will have varyingspeeds which tend to produce a harmonic motion with gradual changes eventhough they occur rapidly. The feed controls select the change incondition of the motor from a slow drive to an accelerated drive and upto a top speed limit condition. As a preliminary to feed stoppage thefeed controls select two stages of motor braking or slowdown to thenormal slow speed drive.

Another object of the invention is to provide improved electronicstorage and programming means for the feed control devices. As iscustomary with the feed control by a tape, the tape is arranged with aplurality of longitudinal channels wherein perforations appear usuallyarranged diagonally for the various stopping positions arrangedprogressively along a form. For example, the stopping positions for ahead space, the first item, and the first total may be controlled bythree holes, the first of which is in channel 1 of the tape, the secondis farther along the channel 2 and the third is in channel 3. In thepresent instance the tape control is further complicated by the desireto detect when a long skip is about to take place and to have suchinformation on hand in connection with each of a plurality of channels,any one of which may be selected according to the arrangement of recordcards in the printing tabulator and the control therefrom. As thecontrol tape per-' forations pass the brush stations each channeloperates electronically to set up a reading of its skipping distance bypositional thyratrons. no skips are called for but the record iscontinually spaced, the thyratrons for channel 1 would react as follows:The first thyratron is energized from the interlock brush which will berecalled as the first brush encountering the perforation. The secondthyratron is energized from the slowdown brush which will be rememberedas the intermediate brush. When the second thyratron is energized itputs out the first one. The third thyratron is energized from the stopbrush which is the last one reached by the hole in channel 1, and it inturn puts out the other two thyratrons before going out itself. Thiscycle is repeated and a similar electronic cycle is provided for each,channel. The reason for this form of electronic program or storagearrangement is that if at any time a skip to 1 is called for and it isfound that the first thyratron is energized, connections are alreadyestablished thereby and it is known that the length to be skipped isless than 3 /3 inches and requires no extra loss subcycles, but sincethe second thyratron is ineffective it is evident that the skippingdistance is more than a short interval and it is evident that ahigh-speed start is called for. From the foregoing it is apparent thatwhen the printer signals the paper feed devices for skipping under thecontrol of a certain channel, that is for a skip to a heading, an itemline or a total line, the distance to be covered in connection therewithis immediately detected because of the condition of the three relatedthyratrons, which in effect signal the starting point and the amount ofdistance of the skip which is about to take place. All this adds up to asaving in time and the possibility of actuating fast electronic controlsfor varying the speed of the drive motor and the clutching anddeclutching of the drive connections.

Another object of the invention is the provision of electronic devicesfor governing feed control in cooperation with an electric switch set inaccordance with the known length of each form on a continuous strip. Theform length selector is arranged with three positions in which the firstposition is for form lengths in excess of 3% inches (usually 20 linespaces). When the switch is on the second position, the form is between3 /3 inches and 9 line spaces in length and the third position isindicative of forms shorter than 9 line spaces. This form length switchis a kind of predictor for aiding For example, even if the speed controldevice to readily determine how changes between high and low speedoperation are to be carried on even before the printer sets up a demandfor spacing or skipping control.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in the accompanying drawings,which disclose by way of examples the principle of the invention and thebest mode which has been contemplated for applying that principle.

In the drawings:

Fig. l is a perspective view showing the main components of the feedingdevice and the drive connections thereto.

Fig. 2 is a left side elevation view showing the control tape and thethree cooperating sets of control brushes. This view also illustratesthe mounting of the drive motor and the connections therefrom to thepairs of tractor pin feed devices.

Fig. 3 is a side elevation view showing the random type clutch and theengaging and disengaging control magnets.

Fig. 4 is a sectional elevation view taken along line 4-4 in Fig. 3 andshowing the interior construction of the clutch.

Fig. 5 is an exploded perspective view of the interior parts of theclutch showing the ratchet wheel control over the inner pry bar forengaging and disengaging the interior drive elements.

Figs. 6a and 612 when taken together provide a front elevation view ofthe entire width of the paper feed unit.

Fig. 7 is a timing chart showing the sequence of operation of thecontrols cooperating with the printer and the paper feed devices.

Figs. 8a to Be when taken together form a wiring diagram showing theelectrical and electronic controls for the feeding devices.

Turning again to consideration of the main framework of the carriage, itwill be noted in Figs. 2, 6a and 6b that the main vertical side frames50 and 51 of the feed unit are attached at the sides of frame casting 40and spaced thereby to hold many of the feeding controls and the crossshafts between these main frames.

Attached to side frames Sal and 51 are a number of brackets for holdingseveral sub-assemblies for different feed controls each of which iscoordinated with the feeding devices in general. On the right sideframe, Fig. 6b, there is a bracket 54 which serves to hold the magneticbrake housing MC which is in cooperation with the main tractor driveshaft 55. Attached to the inner face of the left side frame, Fig. 6a} isa bracket 56 for supporting the parts cooperating with a drive clutch.On the outside of frame 50 are a number of supporting devices includinga bracket 57 for holding the differential drive gearing including theworm gearing for the vernier line adjustment device. Another form ofbracket or auxiliary frame 58 is the support for the three sets of tapesensing brushes and the cooperating contact rollers and driving pin feeddrum for operating the tape. A third frame 59 is supported by studs 60and it projects to form bearings for receiving projecting shafts to holdcertain of the drive gears. Extending across the paper feed unit areseveral shafts and bars which not only support feeding devices, but alsoact as stiffening means between the frames. One such shaft is the shaft62 which is the mounting means for the upper pair of tractor feeddevices. Another such device is the bar 63 which acts as the platen tosupport the record forms when they are receiving the blows of the printrecording heads.

The printer with which the paper feed is illustrated is of the kindinvolving a wire printer operating in serial order at high speed and isset forth in detail in copending patent applications Serial Nos.479,106, filed on December 31,1954, and 479,107, filed on December 31,1954.

In Fig. 2 it is seen that the feed devices are driven by a motor M whichis fastened to the top of the upper casting 40. A blower B, Fig. 6b,keeps the motor cool. This motor M is of a special variable speed typewhich is disclosed more fully in the copending application Serial No.476,655, filed on December 21, 1954, by W. F. Morgan. On the motor shaftis a pulley 66 for the main drive belt 67, Fig. 6a, which is of theinner toothed type or Gilmer timing belt form for a more positive driveto a toothed pulley wheel 68 loosely mounted on the drive shaft 69 butconnected to a clutch drum 70. Through the action of the clutch controlratchets 71 and 72 and other parts, the drive of the continuouslyrotating drum 70 is at times communicated to the drive shaft 69 whichextends to the left, Fig. l, to the tape feeding pin wheel or drum 73and a gear 74 which is the first of a train of gears in the drive.

The drive connections are not direct to the continuous strip advancementtractors but are made through two in- :direct connections for two mainreasons. The first reason for indirection is to provide a planetary formof connection wherein vernier adjustments or slight variations maybemade in record to printer relationship. And the second reason for thecircumlocutionary drive is to provide means for a change from 6 to 8lines per inch of spacing whenever closer printing is desired.

The drive continues from gear 74 and through a loose idler gear 76 whichis in mesh with a gear 77 which is loose on line space adjustment shaft78 but fastened to a hub 79 which also holds the loose continuouslyrotating part 80 of a toothed clutch 8081 normally connected by theshifting action of a lever 82 which carries rollers 83 to open theclutch only on occasion for manual adjustment. The drive continuesthrough clutch disk 81 which has on it a plate 84 with brackets 85, 86and 87 carrying planetary driving connections. A worm gear 88 and ahelical gear 89 are on a short common shaft 90 suspended betweenbrackets .85 and '86. The former is in mesh with a worm wheel 91fastened to shaft 78, and the latter is in mesh with a mating helicalgear 92 which is fastened to a shaft 93 extending through bracket 87 andcarrying a spur pinion 95 which rolls around a gear 96 on a tube 97fastened to the Vernier adjusting knob 98 but loose on shaft 78. Theouter line space knob 99 is fastened to shaft 78.

The drive is ordinarily through the worm gear 88 which is not thenrotated on its axis but instead swung around bodily with shaft 78 as thecenter and the helix of the worm as a drive tooth of the gear 91. Inother words the drive is through clutch 8081, frame 84,

worm 88, worm Wheel 91, shaft 78 and over to a gear 100 also fixed toshaft 78, and then on further in the driving train.

At this point it is well to note how a Vernier adjustment or slightvariation in the position of the record material is made relative to theprinting line. To do this the lever 82 is operated to open clutch 8081and the Vernier knob 98 is turned one way or the other to lift or lowerthe paper relative to the printer. When the knob 98 is turned, theconnected gear 96 is also turned and communicates movement to themeshing pinion 95. Since pinion 95' is on shaft 93 with the helical gear92, the latter is revolved and rotates the associated gear 89 which inturn rotates the worm gear 88. This motion serves to vary the angularrelationship between the plate 84 which is the holder for the worm gear88 and the worm wheel 91 which is fastened to the feed driving shaft 78.There is thus effected a slight change in relationship between the teethof the clutch members 80 and 81 which is taken up the next time thatthey are joined. This change in relationship is in effect a changebetween the relationships of the driving gear 74 with respect to thedriven spacing gear 100. The planetary arrangement including worm 88remains in constant readiness for .ordinary line spacing and skipfeeding movement regard- 6 less of the relative adjustment through thevernier knob. All that is required is that after the slight adjustmenthas been made the lever 82 be manipulated again to engage the clutchparts -81.

A frictional type of spring finger or detent 101 is fastened to the sideof plate 84 and carried around with clutch member 81. This detentextends over into contact with the periphery of a line space detentplate 102 fastened to the side of clutch member 80 and formed with aseries of regularly spaced notches into which a V-shaped extension ofdetent 101 projects and is located as the knob 99 is turned by hand forline space adjustment. Detent 101 snaps into notch after notch when theline space knob is adjusted, and this serves for definite limitation ofthe desired number of manipulated spaces.

For line space adjustment, the driving train of gears is operateddirectly by the outer knob 99. This knob is fastened to shaft 78 andthere is direct communication of the rotation given the knob to thedrive gear at the other end of the shaft.

Now that it has been seen how the driving motion is communicatedindirectly from gear 74 to gear 100, Fig. 1, through the intermediateplanetary adjustment devices, it is possible to trace the drive further.Gear 100 is seen to be in mesh with another gear 104 secured to theshaft 105 which is the axis for the idler 76 already mentioned. Thisshaft 105 projects towards the right and, at that end carries anothergear 106, which is fastened thereon and in mesh with a wide gear 107fastened to a sleeve 108 slidably mounted on a shaft 109. Normally thewide gear 107 is positioned as shown to communicate the drive of gear106 to another gear 110 which is loosely mounted on shaft 105 butconnected to a collar 111 which also carries a slightly larger gear 12.Gear 112 meshes with gear 113 which is fastened to the shaft 55 alreadymentioned as being the driver for the two pairs of sprockets serving toactuate the pin feeding tractors. In other words, when wide gear 107 ispositioned as shown, there is a rather direct communication of thedriving motion through gears 106, 107, 110, 112, 113 and shaft 55. Thedriving connections mentioned are proportioned for spacing six lines tothe inch on the record strip R adjusted by the feeding tractors. When itis desired to change the relationship so that the motion is reduced toget a greater number of lines per inch, then the gear 107, and a pinion114 connected thereto through the sleeve 108, is shifted to the right todisengage the connection to gear 110 and instead to establish a moredirect connection with gear 112. This is done to get a spacing of eightlines per inch. The drive connections then may be followed from gear 106through gears 107, 114, 112, 113 and sprocket shaft 55.

The choice between 6 and 8 lines per inch of spacing is made by theoperator and the gearing 107, 114 is shifted manually before the machineis brought into operation and, therefore, the relationship between thespacing of print on the continuous record form R and the related feedcontrol tape TP may be selected in the usual fashion by proper spacingof the feed control perforations 116 in the tape.

Whenever the drive shaft 55 is rotated, the motion is communicateddirectly to the upper pair of pin feed tractors UT1 and UTZ which haveextending pins mounted on chains to engage several of the marginal pinfeed openings along the sides of all plies of the continuous recordmaterial R. The motion of the tractor pins upward serves to advance thematerial upward past the printing line which is coincident with theplaten bar 63. In order to communicate the driving motion to the lowerpair of feed tractors, the shaft 55 is provided with a pair of attachedsprockets 118 onto which is drawn a pair of belts 119 and 120 fordriving on opposite sides of the feed device. These belts 119 and 120are of the positive type which are formed with inner toothedconstruction to cooperate with precise timing relationships with thedriving sprockets 118 and a similar pair of sprockets 121 which arefastened near the ends of a shaft 122 which is the driver for the lowerpair of pin feed tractors LTl and LT2. These lower tractors also eachhave several pins engaging simultaneously in the marginal openings ofthe record material. Thus the four tractors serve not only to carry therecord material rapidly away from the platen, but also help to bring thematerial out of the magazine and into print receiving position Withouttearing the marginal areas when operating at high speed.

In order to aid in slowing down the rapid advance of the record materialand to aid in bringing it to a stop with gradual deceleration, thedriving means is provided with a brake at the end of the main tractordrive shaft 55. On the right in Fig. 1 it is shown that the shaftprojects into a brake unit BR. This brake construction is better shownin the right of Fig. 6b where it is noted that the bracket 54 on sideframe 51 holds the stationary part of the brake unit. On the outer endof shaft is secured the rotating disk 124 which is keyed thereon and issubject to axial movement when the interior coil MC of the brake isenergized by closure of contacts R48-15, Fig. 8c. The brakingconstruction is similar to that shown in detail in the copending patentapplication of J. M. Cunningham et al., Serial No. 477,286, filed onDecember 23, 1954.

Now that the complete driving connections have been traced in a generalway, it is believed advisable to return to consideration of how the mainoperating clutch 7172 is constructed and controlled by the double coilstart and stop magnets ST and SF. The parts for this clutch device areshown in Figs. 3, 4 and 5. It is pointed out hereinbefore that the leftside frame 50, Fig. 6a, is provided with a bracket 56, and it is on thisbracket that a bar 124, Fig. 3, extends to hold the pairs of coilsconstituting the start and stop magnets ST and SP for the clutch. Alsoextending from bracket 56 is a stud 125 which acts as the supportingmeans and axis for an armature pawl lever 126. The pivot 125 iscentrally located on a line between the two control magnets. Thearmature plate 127 fastened to lever 126 is placed directly beneath thecores of the magnets on either side. When in the normal stopping controlposition, the lever 126 is rocked upward at the left by the stop controlmagnet SP and when operated for clutch engaging or starting control, thesame assembly is rocked upwardly at the right in a counter-clockwisedirection by the action of start magnet ST. A contact 128 is closed bycounterclockwise motion of lever 126 whenever the start magnet ST ismade effective. The rocking motion of lever 126 is limited by anadjustable stop stud 130.

At the right end of lever .126 there is formed a tooth' shape 131 whichcooperates with the ratchet teeth on the wheel 71 which is one of a pairof relatively movable ratchet control clutch wheels 71 and 72. Thecompanion ratchet wheel 72 has teeth facing in the opposite directionand is normally engaged by a toothed clutch pawl 132 which is formedwith a bent lug 134 overhanging the top of lever 126 to partake of itsmovement. A coil spring 135 is coiled around the pawl shaft 136 andtends to hold the pawl 132 down into engagement with the teeth ofratchet wheel 72 and prevent it from rotating in a clockwise direction.When the lever 126 is operated counterclockwise 'by energization of thestart magnet ST, it not only lifts the tooth 131 away from ratchet wheel71, but it also actuates pawl 132 through the lug 134 to disengage pawl132 from the teeth of the other wheel 72.

The object of releasing the two clutch wheels 71 and 72 is to allow theheavy spring 138 to operate and tend to draw togetherthe two wheels inopposite directions a slight amount which serves to exercise-an outwardcamming action on a pair of inner wedges or operating dogs 139 and 140which have outwardly projecting fingers 141, 141 and 142, 142 forengaging the inner circular area of the hollow clutch drum 70. Spring138 is at one end connected directly to the wheel 72 and at the otherend it is connected to a stud 143 which projects through a cammingmember or pry bar 144 and also projects into a slot 146 out into theother ratchet wheel 71. Member 144 is pivotally mounted on wheel 72 bymeans of an eccentric stud 147 which is adjustably rotated and lockedinto position by an attached plate 148 which is formed with an arcuateslot 149 through which projects a screw 150 to tighten the plate asadjusted. The position of the eccentric pin 147 is critical because thelower end of pry member 144 is formed with an overturned projection oroperating piece 151 which contacts with the left side of the lower end.of the clutch engaging member 149. The two members 139 and 140, Fig. 4,are loosely held in a container 152'which is secured to a bushing 153fastened to the drive shaft 69 so that the two wedging parts 139 and 149are not provided with any fixed pivot but rather cling to the circularinner wall of ring 152 and are held in an inwardly clinging position bya weak spring 154. A similar groove-d retainer 156 confines pry member144 axially. The two wedging parts 139 and 149 are in an abuttingengagement at the top as shown in Fig. 5 where the upper horizontaledges come together along the line 155. It is at this point where thewedging members are locked relatively to each other to in effect bespread out and cause the four fingers thereon 141 and 142 to come intofirm engagement with the inner surface of the continuously rotating drum70. The train of action may be followed by nothing that release of thetwo ratchet wheels causes relative motion thereof with wheel 71 comingin a counterclockwise direction while wheel 72 moves slightly in aclockwise direction. The result is that member 144 through the action ofthe strong spring 133 is rocked slightly counterclockwise about pivot147 and tends to pry wedging member 140 outward through the offsetportion 151. At the same time the other wedging member 139 is alsoshifted outwardly by the action of a pair of inwardly projecting studs157 which are held on wheel 72 and embrace the lower end of member 139.With the two wedging members 139 and 140 being spread apart'or movedout- -wardly at the lower ends, they are in effect rocked about point155 and are crowded into firm engaging connection with the rotating drum7%) and motion of the drum is communicated from the drum through the twowedges and through the member 144 and studs 157 to the gear 72 andattached bushing 153 and into the shaft 69 attached thereto. Then theclutch parts and shaft 69 are rotated in a counterclockwise direction asshown in Fig. 3 as long as the teeth 131 and 132 of the armature leverand pawl are held raised away from the ratchet wheels. However, as soonas the start magnet ST relinquishes control and the stop magnet SP isenergized, the lever 126 is rocked in a clockwise direction and the twopawls are dropped into the ratchet teeth, whereupon tooth 131 steps thecounterclockwise motion of wheel 71 and through the pin and slotconnection 146, Fig. 5, operates member 144 to rock it in a clockwisedirection and shift the lower end 151 to draw away from the lower end ofwedging member 140 and thereby free the connecting parts from the drum70 which continues to move in a counterclockwise direction, Fig. 3. Asthis disengaging operation takes place, the other ratchet wheel 72 iscarried along for a slight extent with one of the abutting teeth goingbeyond the left of pawl 132 but prevented from being retracted by theaction of spring 138 because the pawl snaps into place before the wheelcan move clockwise.

Although the various sections of the clutch parts have been referred tohereinbefore as upper and lower portions ofthe clutch members, it may bepointed out that the clutch parts are operable in all positions ofrotation. In other words, the clutch is of the form known as a randomengaging clutch wherein the parts have no fixed relationship relative tothe driving drum, and the inner clutch parts are operated universally byouter engagement with any of the plurality of teeth on the ratchetwheels. For a high-speed device this is important because there is nonecessity for any parts to return to a home position. The clutch isavailable to start from any position and to stop at any position.However, the ratchet teeth on the clutch wheels have a relationship witha line space movement of the drive connections, so that rapid operationof the start and stop magnets is productive of single line spacemovement. In order to produce such a rapid switch from the start to thestop operation, there is provided the latch contacts or clutch switchcontacts 128 which are closed by lever 126 upon a slightcounterclockwise start movement so that the clutch is barely releasedbefore contacts 128 are closed to call stop magnet SP into action for asingle-space operation.

It is noted hereinbefore that a control tape TP is provided to furnish aflexible form of predetermined programming for locating the record formswith respect to the printing line so that heading print blocks, itemprint and total print are started and stopped wherever desired on theforms. There is a tape TP produced for each type of form and for therespective length of form. The tape TP as shown in Figs. 1, 2 and 6a isan endless paper band which is either equal in length to the relatedform or a multiple of the form length in the cases of short forms. InFig. 1 it is seen that the tape is a nar row paper band which is drivenby the pin studded drum 73 with the pins 158 thereon cooperating with acentral line of feed perforations punched in the tape. The tape isadvanced in synchronism with the movement of the record strip R anddescribes a triangular path in moving around an idler pulley 159 at therear and then passing successively around contact rollers 160, 161 and162, the latter being on the feed drum 73. The three contact rollers orcylinders 160, 161 and 162 are placed opposite three lines or sets oftape sensing brushes, interlock brushes IN, speed reducing or slow-downbrushes SL and finally the upper set of stop brushes ST.

As shown in Fig. 6a the three sets of brushes and co operating contactrollers are supported outside the left side frame on a separate smallframe 58 fastened to frame 50 by extending studs and brackets. The driveshaft 69 extends through frame 58 and carries drum 73 which extendsoutwardly. The other two contact rollers 160 and 161 are supported atthe inner end on hearings in the frame and project outwardly withoutsupport at the outer ends.

The tape TP, Fig. 2, is held taut by the holder for the rear idlerpulley 15 which comprises an arm 164 which is rocked to the properangular position and secured to the side frame 50 by means of a nut andlock washer 165 acting on a hub of the arm. When it is desired to changethe tape all that is necessary is to loosen the arm 164 and slip thetape outwardly over the four guide rollers, i. e., after all sensingbrushes have 'been rocked out of cooperation with the tape. When a newtape is inserted, the arm is adjusted angularly to hold it taut.

In Fig. 2 it is also seen that the three lines or sets of tape sensingbrushes are mounted in a separately movable frame 166 pivoted at 167 ona stud projecting from the frame 58. The frame 166 is in the form of 'achannel with a V-shaped cross section and has side plates for confiningthe ends of insulation blocks 168 three of which are spaced between theframe side plates to hold the sets of sensing brushes. When frame 166 isin the operating position it closes the contacts of a switch 169fastened to frame 58 and it is in this position that a latch 170 pivotedon the top of the frame catches over a square stud 171 extendingoutwardly from one of the main side 10 frames 50. When it is desired tochange the tape, the latch is lifted and then the frame 166 rocksclockwise until it abuts against a stop rod 172. In so doing it opensthe contacts of switch 169 and this prevents operation of the feedingdevices while the operators fingers are in the mechanism.

Referring to Fig. 6a it is seen that, in addition to the insulationblock 168 for holding the line of brushes, there is also a comb-shapedinsulation member 173 which confines each sensing brush to a particularpath on the tape. These paths around the tape are also termed channelsand it is in these channels where the tape feed control perforations areplaced differentially to predetermined various stop and start positionsrelated to positions on the continuous record forms R. It may be notedthat in the comb formation of guide block 173 there are 13 notches, 6 onone side of the tape feed pins 158 and 7 on the other side. The extraposition, or 7th position at the extreme right, is used for a commoncontact brush which carries current to or from the contact roller. Theother 12 brush positions are used mainly for several skipping controlsand one is reserved for overflow control.

Since the tape TP is moved in a counterclockwise path, Fig. 2, aperforation 116 therein in any channel passes in succession first underthe related interlock brush IN at the bottom and next passes theslowdown brush SL in the middle and finally reaches the stop controlbrush ST at the top. Since the tape is moved along with the record stripR during line spacing operation, the particular tape perforation of acertain channel may be anywhere short of the stop position brushes whena skip is initiated related to that particular channel. It is by means.of these spacings of the three brush sets relative to the tape that thecontrols are preconditioned before skipping is initiated by the presenceor absence of controls initiated by the particular tape hole passing ornot passing the two lower sets of brushes. For example, if a certainchannel is selected and it is immediately determined that the particulartape hole has not already passed the related lower brush IN, it is knownimmediately that the skip is going to be more than 3% inches in lengthand therefore necessitates both movement at high speed and the omissionof at least two subcycles of printing actuation to allow time for thislong movement. On the other hand, should the skip initiation find thatbrush IN has been activated but that related brush SL has not exercisedany controls, then it is known that the tape control perforation standsbetween the two brushes and the skip involved is longer than nine linespaces but shorter than twenty line spaces. Therefore, the skip is tostart at high speed and involve a shorter loss of printer time. Should askip initiation find both lower controls activated, then that is a sigmthat the skip is to be a very short one involving less than: nine linespaces and it is to proceed at slow speed and involve a still shorterloss interval of printer time or no loss at all.

At this point it is well to comment upon the effect that the cardreading printer has over the feed devices because it is the printerwhich responds to the punched record card 7 control and prints on therecord form according to how many lines of heading data, item data andclasses of totals are called for by a particular group or groups ofcontrol cards. The printer has group control devices, heading cardcontrol by X and no X punchings in the cards and program controls forvarious classes of items and totals such as minor, intermediate andmajor controls.

These controls originating within the card reader and printer areproductive of impulses which maybe used selectivelyto control thespacing or long feed skipping operations of the record'strip feedingdevices.

The channels of the tape TP are selected by the record card controls inthe printer. As the cards feed they are sensed not only to select thedata to be printed, but

also the disposition of such printing by placement on a form. In mostinstances the printer initiates feeding for line spacing or skipping andthe tape controls effect stoppage as determined by the holes in thetape. The exception is the overflow control whereby the tape bothinitiates and stops an ejection of the record material from the end ofone form to the top of the next form. Tape channel selection ispluggable and of selective control from a number of card controlledsources. It may come from X holes in heading cards, or digit selectionholes in any card, or class of totals on total cycles, or by groupchanges without total printing. These forms of channel selection controlare set forth at length in the Mills et al. Patent No. 2,531,885, issuedon November 28, 1950. Other patents of the tape controlled feed devicevariety include Rabenda Patent No. 2,569,829, issued on October 2, 1951,Bakelaar et al. Patent No. 2,684,746, issued on July 27, 1954, and theCunningham et al., Patent application Serial No. 477,286, filed onDecember 23, 1954.

It will be noted hereinafter with reference to the wiring diagram thatthe feeding controls for double space, triple space skip to 1," skip to2, etc., are all pluggable to receive control impulses from the cardreader and printer. They take precedence over each other in the ordermentioned with single line spacing dominating all. The skip to controlsrefer to the tape sensing brushes as they are picked up in successiveorder so that when the skip to 5 control is plugged, it means that thefifth tape brush is to sense a tape perforation and control the stopmagnets regardless of tape perforations in all lower channel positions.Ordinarily it is for only the advances of four or more spaces that skipstop perforation control is put in the tape to determine where a headingis to start, where item impressions are to start, or where a totalimpression is to be placed.

When there are too many related items to be recorded on one form it isnecessary to put the overflow items on a second form. In such cases theend sensing brush or twelfth brush of the stop brush set, in cooperationwith a perforation at the side of the tape, determines where theoverflow skip is to start. Any predetermined position may be chosen asthe last line of a form and the control tape punched in the twelfthchannel at a corresponding position to initiate overflow skipping.

The feeding devices operate at two speeds which are governed by thecontrol over the variable speed motor which is operable at a recordmovement speed of 75 inches per second for skips of more than nine linespaces, end at the slower speed of 25 inches per second for skips ofless than nine line spaces. These changes of speed since they are notabrupt are smoothed out in a sort or harmonic motion change or gradualvariation from high to low speed. The demand for high-speed operation isautomatically called for by a skip when a tape control perforation failsto make evident the passage beyond the slowdown brushes SL at the timethe skip is initiated.

The feeding devices are provided with line spacing controls for single,double and triple spacing. The selection of control is made by operationof pluggable controls described hereinafter with relation to the wiringdiagram. A single space control is the normal operation and will takeplace invariably in conjunction with serial order printing unless thefeed controls are signaled otherwise.

The line spacing controls involve the use of the commutator 175 bestshown in Fig. 6a where it is seen to be connected to shaft 69 and placednear the outer face of the side frame 50. Cooperating with thecommutator are four sensing brushes best shown in Fig. 2 where they areseen to project radially from an arcuate block of insulation 176 whichis fastened to the outside of frame 50. In Fig. 6a it is noted thatcommutator 175 has a continuous metallic band in one area and a regularseries of separate segments or metal inserts spaced apart the equivalentof three line spaces. Cooperating with the continuous commutator band isa common line space conducting brush LSC, Fig. 2. The other threebrushes LS1, LS2, and LS3 are spaced apart with their operating endstouching the commutator where it has the separated segments. One ofthese three brushes is always active and in contact with a segment andit may be any one of the three. When one is in the active position theother two are spaced one and two spaces re spectively away from othercommutator segments. The wiring controls later considered in connectionwith the wiring diagram are flexible so that upon a demand from theprinter for one line space, such a demand is communicated to theparticular one of the three line space control brushes which happens tobe on an active segment. The wiring connections serve to initiate a pairof impulses to activate the start and stop magnets of the random clutchto cause the shift of one line space which also moves the commutatorsegments to pass from one control brush to another. In the event of asetting for double line spacing, then the control is varied to embracethe brush which stands one space removed from a conductive commutatorsegment. The double space control then calls for a stop impulse derivedfrom the secondary control brush source and this necessitates themovement of the commutator and all connected controls including therecord to a position involving two successive brush sensing stations onthe commutator. In this same fashion a triple line space selectionrequires the cooperation of a spaced pair of line space brushesinvolving the brush which is on a segment and a brush twice removed, i.e., in a position which establishes contact only after two degrees ofmovement of the commutator and becomes effective for stopping after thespacing of three line spaces.

Before considering the electrical and electronic controls of the recordfeeding devices, it is believed advisable to consider the timing ofoperation of the printer. Reference to the timing chart, Fig. 7, showsthat the printer cycle, when considered with a printer of the serialorder impression variety, is subdivided to provide time for thesuccessive impressions to be interspersed between spacing operations. Inthe particular kind of printer used as an illustrative embodimentherewith the printing is effected by four successive impressions of thesame printing head. These impressions are made side by side in the sameprinting line and adjacent to each other in consecutive order from leftto right. Ordinarily after each set of four impressions there is aspacing operation followed by four other impressions from right to left.A sequence of eight print operations may be considered a full cyclewhich falls within 360 degrees of operation. As the chart indicates, forsimple short spacing operations there is no'loss of printer time becausethe printer after making one set of four impressions permits spacing totake place while preparations are in order for recording the next foursets of Impressions. However, when a skipping operation of any lengthintrudes into the printing operation, some additional time must beallowed, but such time is not allotted here in units of a completeprinting cycle. Instead, the time allowed is gaged in fractions of aprinting cycle and only the required number of subcycle portions of timeare given to permit full spacing operation before the printer startsanother series of printing impressions. Therefore it is evident from thechart that the spacing between printer groupings of serial impressionsis not a fixed interval but instead variable for several differentsubcycles of time in accordance with the demands of long skippingoperations.

The wiring diagram shown in Figs. 8a-8e reveals wiring connections andthe controls connected between the printer and the feed unit and alsothe connections between various components of the feed unit and itsdrive motor, so that the regulation of speed and stopping posi- 13 tionsis coordinated between the control tape brushes, the clutches and thedrive motor.

Referring to the bottom of Fig. 8e of the drawings, there is shown afeed driving motor M having an armature 310 and a field 311, relays R312and R313, a relatively low positive potential source 314 and arelatively high positive potential source 315 having a common groundterminal and a number of capacitors and resistors. As shown, the motorcontrols are in the normal condition in which the motor operates at thefirst and lower of two predetermined speeds. When so conditioned, relaysR312 and R313 are de-energized. Certain associated relay contacts ofboth relays are shown closed while others are opened, and then relayR312 (at the upper right corner) picks up upon the closing of contactsR48-11 which are actuated for any skipping operation involving feed inexcess of nine line spaces. The

closure of contacts R48-11 may be considered a first signal calling forthe beginning of acceleration toward the higher speed. Subsequently, theopening of contacts R48-11 which causes the release of relay R312 may bedesignated as a second signal and serves to cause deceleration orbraking to begin.

As shown, the coil of relay R313 is always connected in series with aresistor 317 across armature310, but during low-speed operation, thevoltage across the relay coil is too low to cause its pickup. Furtherdelay for relay R313 is provided by the capacitor 318 in combinationwith resistor 317.

A resistor 319 is in series with low potential source 314 and adjuststhe low speed of the motor; Another resistor 320 improves the low-speedregulation of the motor. Resistors 321 and 322 limit the second or highspeed of the motor, and the latter provides close regulation of thesecond speed.

A rectifier element 332 is in series with the low potential source 314to prevent current flow upon the closing of relay contacts R3121).

As explained in greater detail in the copending patent applicationSerial No. 476,655, filed on December 21, 1954, by W. F. Morgan, themotor controls assume five different conditions, the first of which isat slow speed and arranged with the parts as shown in Fig. 8e.Thereafter, the contacts are so shifted as to produce in succession anaccelerated condition, a top-speed-limiting condition, and first andsecond braking conditions.

In the first low-speed condition, the armature 310 and field 311 areconnected in series with rectifier 332 and resistor 319 between the lowpotential source 314 and the ground because relay contacts R312d andR313d are in normally closed positions. With contacts R312a closed,resistor 320 is shunted across armature 310 to improve speed regulation.Adjustable resistor 319 provides means to adjustthe speed of the motorto a desired first value. 1

When the feeding devices signal the demand for a skip feed of over nineline spaces, it is a sign that acceleration is to begin. Upon theclosure of contacts R48-11, thyratron V6 and relay R312 are picked upand contacts R3121) and R312c are closed so that armature 310 and field311 are connected through normally closed contacts R313b between thehigh potential source 315 and the ground. No resistors remain in theseries path, and resistor 320 is made ineifective by the opening ofcontacts R312a. Accordingly, the motor rapidly accelerates from thefirst slow speed to the second high speed.

The relay R313 is brought into action at high speed to prevent the motorfrom exceeding a predetermined speed. Closure of contacts R313a puts theresistor 321 in shunt across armature 310. The opening of contacts R313bputs resistor 322 in series with armature 310 and field 311. Bothresistors act to limit the speed and adjustable resistor 322 providesadjustment.

When the tape sensing brushes of the second set sense that the record iswithin nine line spaces of the stopping point, electrical connectionsare made resulting in the picking up of relay R45 and the opening ofR45-4 to take ofi the bias supply and thyratron V5 goes on and as aresult the connected thyratron V6 is extinguished and the connectedrelay R312 is de-energized, and this is the second signal calling forthe beginning of braking due to the release of relay R312. Relay R312 isdesigned to open its contacts R312b and R312c disconnecting armature 310from the high potential source 315 at a time shortly before contactsR312a and R312d close. A voltage is generated across armature 310 havinga polarity so that current continues to flow through resistor 317 and acoil of relay R313 in the same direction. Therefore, relay R313 remainsenergized and its contacts R313a and R313c remain closed for the firstphase of the braking operation. I

The second phase of braking begins with closing of contacts R312a and312d. Aramature 310 and field 311 are now in series with resistor 320between the source 315 and the ground. Resistors 321 and 322 are shuntedacross resistor 320. The armature is then connected with the oppositepolarity. Accordingly, a relatively large but limited current flowsthrough armature 310 in the opposite direction from the 'previous flow,and the motor develops torque in the opposite direction and is rapidlydecelerated.

As the armature slows down, the generated voltage decreases untilinsufficient to hold relay R313 picked up. When the relay contactsreturn to the normal condition, the contacts R313b and R313d close andcomplete the original low-speed circuit.

The Wiring diagram, Figs. 8a-8e, is shown in five sections relating ingeneral to different parts of the feed unit electrical controls as theyare related to the printer. Fig. 8a shows many of the controls in theprinter. Fig. 8b shows the means for selecting skipping and line spacingcontrols. Fig. 8c shows the line space commutator and carriage stopdevices. Fig. 8d shows the tape sensing brushes and the electroniccontrols cooperating therewith. Fig. 82 shows the connections to thestart and stop magnets of the random clutch and the variable speed motorcontrols.

Turning to Fig. 8a first for consideration of how the printer iscontrolled and how the record feed unit influences such control, at thetop of this figure, it is seen that there is a series interlock circuitinvolving a wire 335 from the plus 46 volt source, and this wire is partof a series circuit involving the feed unit contacts 295 which will beremembered as the contacts closed when the slide rods are fullyinserted, showing that the feed unit is properly latched onto theprinter. Other printer contacts 339-333 are in the same interlockcircuit which energizes the relay coil R1 connected to the minus 46 voltsource. Relay R1 is part of a readying apparatus which must be picked upfrom various sources to indicate that all connections are in readinessfor operation of the printer. When relay R1 is picked up, it closescontacts R1-a in series with another readying relay R2. This secondarycontrol circuit includes stop key contacts 336, relay contacts R1a,start print contacts 338, and relay contacts R7-a normally closed. Theseconnections all influence the pickup coil of relay R2. When the relayoperates, it closes associated contacts RZ-a in series with the holdcoil and then the relay is sustained by either connections through wire337 and relay contacts R7-b, or wire 339 and the cam contacts B14.

Contacts controlled by relay R2 are in series With one of a pair ofclutch magnets for influencing the operation of the printer. These twoprinter clutch controls are identified as magnets AM and BM, and theformer is for controlling a clutch with timing cams which are mostly ofan electrical nature. The second magnet BM controls a clutch forconnecting cams which are mainly of a mechanical nature for operatingvarious trains of connections and also for operating the main printerdrive shaft. The controls over these two clutch magnets AM and BM arearranged so that the former has precedence over the latter. In otherwords, magnet BM is only picked up as an aftermath of the operation ofmagnet AM. Therefore, it will be realized that by putting variouselectrical controls in circuit with magnet AM, the whole printeroperation will be influenced.

A number of the feed unit controls for suspending or varying theoperation of the printer are shown connected to influence the operationof printer clutch magnet AM. They are to be mentioned here only brieflyand to be more fully explained hereinafter. The series circuit forenergizing clutch magnet AM includes a pair of contacts R2-b which areoperated to close under control of the ready magnet R2 already mentionedin connection with the preparing aspect of printer control. Also inseries with AM are the normally closed cam contacts A1 and normallyclosed relay contacts R48-2 which relate to skipping control and areopened whenever a skipping operation is being performed by the feedingdevices. Another control is that of the normally closed contacts R5112,also a series connection which is opened during overflow skipping tosuspend operation of the printer during form to form ejection.

Around the series circuit already mentioned in connection with magnet AMis a secondary series circuit involving the constantly moving cam shaftand cam contacts C9. This circuit has in parallel two relay contactsR454, and R464, the former being called in by the slowdown brushes ofthe tape sensing devices so that the printer is restarted in operationduring the short slowdown period. The second pair of contacts R46-1relate to a relay which is influenced by the interlock tape brusheswhich are engaged when a stop perforation is 3 /3 inches from the stopposition and indicating that the record material is nearing the stoppingpoint and preparations may be made for bringing the printer intooperation. Contacts R46-1 provide this advance printer pickup control tomagnet AM in conjunction with a shunt connection around them involvingnormally closed contacts R483 which relate to the relay R48 which iscalled into operation for all skipping functions. Therefore, whenskipping causes R48-3 to open for a long skip which disables printerclutch magnet AM, there comes a time in the operation when the skip iswithin 3% inches of being completed and then relay contacts R464 areclosed to again start the printer moving through a series of steps whichtake long enough so that when record feeding has been terminated, theprinter will be in full motion and ready to continue recording withoutloss of time.

The second printer clutch magnet BM is seen to be in series with camcontacts A2 which are operated whenever the first magnet AM engages todrive the cam contact shaft.

It is recalled that certain relay contacts R712 and R712 have someinfluence over the readying circuits of the printer, Fig. 811. At thetop of this figure it is shown that in series with the relay R7 are formcontrolled contacts 238 which are controlled by a lever which detectsthe passage of the end of the record form. Should the record materialbreak, or for any reason be torn or interrupted, the contacts 238, Fig.8a, close and illuminate a warning light 340 and pick up the relay R7which operates its contacts to break down the readying and runningcircuits of the printer.

In Fig. 8d it is seen that the three sets of tape sensing brushes IN,51. and ST cooperate with the respective contact rollers 160. 161 and162 to control the feeding unit as determined by perforations in thetwelve channels of the control tape TP. There are eleven brushes in eachset plus a twelfth brush OF in the stop set of brushes ST, and. thisextra one is for overflow detection. The first eleven are selectedaccording to the kind of stopping control it is desired to exerciseunder control of the record cards and the printer. Each of the elevencontrols may very well have a differently arranged perforation to causeeleven different kinds of control and eleven different final stoppingpositions of the record material so that recording may start ondifferent heading item and total lines. The means for selecting one orthe other of the eleven controls are illustrated in Fig. 8b.

Along the left side of Fig. 8b it is seen that there are arranged fromtop to bottom a series of relays starting with relay R29 and continuingdown to relay R44. These are termed skip to controls, and they areprovided to afford eleven different electrical pickup means, one foreach of the tape sensing channels and they are picked up to determineunder which of the eleven brushes the record is to be skipped. At theupper left corner of Fig. 8b, it is seen that all skipping control isaffected by the operation of cam contacts B10 and the normally closedrelay contacts R19a. The last mentioned contacts are opened during stopcontrol to disable all skipping operations.

The eleven skip to controls are similar in operation and arrangement sothat a description of one applies to the others as well. The pickup coilof relay R29, which is controlling over the first channel of the tapesensing brushes,-is seen to have connections to cam contacts B11 and toa plug socket 341 and plug connections are made to carry a pulse theretorepresenting some change in the card reader or printer machine. From thecard it may be from an X hole or any digit selector, and then on theother hand, it may be derived from a group change or total takingoperation. In any event, the impulse coming to socket 341 is anindication that a change in relationship of heading, item or totalprinting requires a demand for paper spacing to the control of the firstchannel which is usually devoted to skipping to the first heading lineof the first heading. When relay R29 is picked up, it closes contactsR29-1 in series with the holding coil, and this coil is furthersustained by cam contacts B10. Relay contacts R52-1 are arranged inshunt around R29-1 and they serve to select a skip to 1 when a restorekey is operated. Other connections through wire 352 are made to theholding coil of relay R29 to determine that an overflow skippingoperation is to stop under skip to 1 control.

Turning again to Fig. 8d, it is seen that relay R29 has three sets ofcontacts, one set in series with an individual one. of each of the threesets of brushes to select one of the eleven in each case. These contactsR29-3, R29-4 and R29-5 are shifted to make effective the brush at theextreme left of each set. In a similar fashion, the other ten relaysRSI-R44, Fig. 8b, are effective to select other of the ten sets ofbrushes. These relays R29R44 are not only effective in connection withthe tape reading brushes, but they also operate any one of an entireparallel set of relay contacts R29-2, Fig. 8b, R31-2 etc., arranged inseries with a common all skips relay R48. It will be remembered thatthis relay R48 has contacts in series with the printer clutch controlmagnet AM, Fig. 8a, and in a similar fashion it has controls in manyplaces throughout the feed unit electrical devices to exercise controlwhenever skipping is or is not taking place. When a stop brush circuitis made, the thyratron V9 is fired and through contacts R29-5, relay R19is picked up momentarily to break space and skip circuits, and indropping out R29 it also opens R29-5 to extinguish V9 and deenergizeR19.

Before considering further the tape controls and manual controls of thefeed unit, it is believed best to point out how line spacing and formfeeding are carried on. In Fig. 8e it is seen that when the printer camcontacts B2 close, a circuit is directed through the normally closedcontacts R544 and R604 to the grids of the two start control thyratronsV1 and V2. These tubes fire and energize both coils of the start magnetsST of the random clutch. This operation of the magnets not only connectsthe tractor drive shafts to the driving motor, but they also operate thelever 126, Fig. 3, to close latch contacts 128 early in the spacingoperation. These contacts 128, Fig. 8c, are seen to be part of a longstop control series circuit involving relay contacts R25-4 normallyclosed, R26-4, R27-4, R48-12 (closed until skipping takes precedenceover spacing), wire 343 to normally closed relay contacts R16a, Fig. 8dand wire 344 extending over to Fig. 8e and into the grids of the pair ofthyratrons V3 and V4 in series with the pair of stop magnets SP forstopping the random clutch. When the tubes V3 and V4 fire, they not onlycall into operation the stop clutch magnets SP but they also cut oifconduction in the other two tubes V1 and V2 related to the start clutchmagnets ST and the same is true conversely. This rapid switchingoperation from control by the start clutch magnets to control by thestop clutch magnets is productive of one tooth space of movement on therandom clutch and this is equivalent to one line space on the recordform. When no other spacing or skipping function is called for, thesingle space skip is automatically effected.

There are also connections provided to effect a single line spaceoperation manually. Depression of the space key shown at the lower lefthand corner of Fig. 8b closes contacts 345 and causes relay R53 to pickup and then to drop out quickly as the condenser in series therewithcharges and gives a uniformly short pulse to the grids of the spacingcontrol magnets V1 and V2, Fig. 8e, because of the closure of relaycontacts R53-4 arranged in shunt around contacts B2.

The machine may be plugged selectively to yield double or triple linespaces in connection with every spacing operation. This is done inconjunction with the commutator 175 and the four brushes cooperatingtherewith as shown in Fig. 2 and also illustrated in Fig. 8c. Thecommutator 175 is so constructed that for each single line space one orthe other of the spaced three line space control brushes LS1, LS2 or LS3rests on a commutator segment. Since the segments are spaced theequivalent of three line spaces apart (but joined in common contact tothe common brush LSC) and the brushes are so spaced that only one brushmakes at a time, during continuous normal single line spacing, the threebrushes take turns in contacting the segments.

Assuming first that it is desired to obtain a double space, then theconnection from cam contacts B15 is plugged to the double spaceselection plug socket 347, Fig. 8b. It is assumed further that the linespace control brush LS1 is the one that is touching a segment when thedouble spacing operation is to be effected. In such a case, thecorresponding relay R21, Fig. 8c, is then ready to be picked up over thecircuit including wire 348, common brush LSC, commutator 175, brush LS1,wire 349, wire 350, normally closed contacts R24-4 and R234 pickup coilR21, cam contacts B12 made early in the cycle and further connections tothe ground. The object is to stop the feed drive after cam contacts B2,Fig. 8e, have started it and after two line space movements have beenperformed, and this requires that the normally controlling random clutchlatch contacts 128, Fig. 8c be disconnected from the stop circuit toavoid single space short stops and that relay contacts of relays R25,R26 or R27 be put in their place to complete a stop circuit through theproper commutator line space control brush.

In preparing the proper stop circuit, cam contacts B12 close early inevery cycle ahead of cam B2 and, in the present instance, serve to pickup relay R21 because brush LS1 is the one standing in contact makingposition. When relay R21 becomes effective, it closes contacts R21-1,Fig. 8b, and establishes a circuit through B10, the R21 holding coil andover to the minus 46 voltage line. It also operates contacts R21-4 andR21-5, Fig. 8c,

to open the coil circuits'of the other two relays R23 and R24. When thecam contact B15 makes ahead of contact B2, a circuit is completedthrough plug wire 346 to the double space hub 347, Fig; 8b, and throughthe contacts R21-6 to pick up relay R26 which is one of three spacetranslation relays. seen that relay R26 then operates to shift contactsR26-4 to transfer the stop circuit to brush LS2 so that when the feeddevice is started and the commutator 175 moves,

it rotates until brush LS2 hits a live segment, and in. this instance adouble space will result before the stopor R24) through contacts B12,and in conjunction with" the plugging from the carriage all cyclescontacts BIS to either double space or triple space, the proper spaceselection relay is set up and then, after the feed unit has started, thebrush selected by the space translation relay R25, R26 or R27 completesthe stop circuit to the stop thyratrons.

It is obvious from inspection of the circuit that had the feed unit beenconditioned with brush LS2 standing on a segment, then relay R27 wouldhave been transferred, and with brush LS3 on a segment then relay R25would have been transferred, causing .a double space in each case.Theerfore, the commutator brushes have a roving type of connection to beeffective for similar controls in any of three conditions.

If the triple space hub 351, Fig. 8b, is connected to the carriagecontrol cam contacts B15, then the selection of the space translationrelays R25, R26 and R27 at the right in Fig. 8b would be alteredaccording to the relay matrix to furnish a stop pulse after a third linespace. Either double or triple line spacing can be called for at anytime and in any squence and all such spacing is performed at the slowrate of speed at twentyfive inches per second of record movement.

A number of B cam contacts have been mentioned hereinbefore and it iswell to note that allcams-for them are of the four lobed variety becauseof the serial printing nature of the printer, i. e., because recordingis done in four steps along the print line. As shown in Fig. 7, theprint cycle of 360 is devoted to eight print subcycles because inprinting there are first four impressions made towards the right,followed by four impressions toward the left, before the print headsreturn to the first position.

Cam contact timing may be given with regard to the timing of the firstlobe of each as follows:

A1350 to 6 BIL-358 to 48 A218 to 48 B1215 to 40 C918 to 35 B1460 to 100B215 to 27 B15--24 to 40 B7-350 to 2 1317-9" to 25 BIO-36 to 86 The Aand B cams repeat in operation every 90"; The C cam contacts althoughthey are also'of the four lobed variety operate twice as fast and repeatin every 45 to have the etfect of an eight lobed cam. i i

In Fig. 7 it is also shown how the spacing and skipping operationsinvolve a series of relay operations before the clutch and othercontrols come into play. Examples are given of a double line space, asingle space skip, a skip of from two to ten spaces at slow speed, and askip of from eleven to twenty-two spaces at high speed which is sloweddown and stopped by successive operation of the slow and stop brushes.It will be noted that'the At the top of Fig. 80, it is,

